The invention relates generally to detecting turn faults in the stator of alternating current (AC) induction motors.
AC induction motors are used in a wide array of applications and processes. An AC induction motor typically includes a stationary portion, a “stator,” and a rotating portion, a “rotor.” In a 3-phase AC motor, power is applied to the stator to induce a magnetic field, causing the rotor to turn and generate mechanical energy. The stator may include any number of “windings,” or wound poles that carry the current necessary to induce the magnetic field. These windings may also be characterized by the “turns” in the winding.
In many environments, the windings in the stator are subject to shorts between the turns of the windings, commonly referred to as “turn faults.” In operating such motors, various algorithms may be used to determine the state of the motor. For example, an algorithm may be used to determine the number of turn faults. The parameters used in these algorithms, such as voltages and currents, may be measured using measuring equipment such as current transformers and potential transformers. Variation in the instruments, such as gain and phase delays, may result in erroneous measurements that lead to false results from the algorithm. Additionally, changes in environmental conditions may also affect the accuracy and precision of the measuring equipment.